Salt Tolerance of Panicum Virgatum and Spartina Pectinata.

Marginal and degraded lands are expected to be important resources in the production of biomass in order to avoid real or perceived competition with food, feed and fiber production.  Globally, there are millions of hectares of salt-affected land available for lignocellulosic feedstock production.  Greenhouse experiments determined the effects of irrigating with water having different levels of salinity and sodicity on seed germination, plant growth, and cation balance in plant tissues in several populations of switchgrass, prairie cordgrass and miscanthus.  The effect of salt stress on seed germination was more pronounced in switchgrass than prairie cordgrass with 31 and 15% reduction, respectively, compared with pure water.  A few populations, including miscanthus, exhibited poor seed germination even in pure water and so reliable conclusions could not be drawn with regards to salt tolerance.  In a two-season greenhouse pot experiment, aboveground dry biomass production in Control treatments was 8 and 21% higher in prairie cordgrass accessions pc17-102 and pc17-109, respectively, than in Kanlow switchgrass.  Kanlow produced greater biomass than prairie cordgrass populations when irrigated with moderately saline (5 dS m^-1) water, although differences were not detected with highly saline water (10 dS m^-1).  Cave-in-Rock switchgrass germination, plant growth and cation balance were severely affected by increasing levels of salinity.  Overall, several prairie cordgrass and lowland switchgrass populations were found to have good germination and high biomass production under moderate to high salt stress and may be good candidates for lignocellulosic feedstocks on salt-affected land.